843 results on '"Ikegami Andersson, Walter"'
Search Results
2. A Generalized Approach to Longitudinal Momentum Determination in Cylindrical Straw Tube Detectors
- Author
-
Ikegami Andersson, Walter, Akram, Adeel, Johansson, Tord, Kliemt, Ralf, Papenbrock, Michael, Regina, Jenny, Schönning, Karin, and Stockmanns, Tobias
- Published
- 2021
- Full Text
- View/download PDF
3. Track Reconstruction with PANDA at FAIR
- Author
-
Papenbrock Michael, Ikegami Andersson Walter, and Regina Jenny
- Subjects
Physics ,QC1-999 - Abstract
The future PANDA experiment at FAIR aims to investigate a wide range of physics processes in antiproton-proton collisions at rates of up to 20 MHz, while employing a purely software-based event filter. To educate the trigger decisions, a full event reconstruction has to be carried out in real time. This challenge is amplified when considering tracks from particles with long lifetimes and displaced decay vertices, which add to the complexity of the reconstruction algorithms. Here, we present modifications to a cellular automatonbased track finder taking detector time-stamps into account in addition to spatial information, as well as several pattern recognition methods for longitudinal track reconstrucion with PANDA’s Straw Tube Tracker.
- Published
- 2020
- Full Text
- View/download PDF
4. Observation of an Isoscalar Resonance with Exotic J(PC)=1(-+) Quantum Numbers in J/psi -> gamma eta eta '
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Using a sample of (10.09 +/- 0.04) x 10(9) J/psi events collected with the BESIII detector operating at the BEPCII storage ring, a partial wave analysis of the decay J/psi -> gamma eta eta ' is performed. The first observation of an isoscalar state with exotic quantum numbers J(PC) = 1(-+), denoted as eta(1) (1855), is reported in the process J/psi -> gamma eta(1) (1855) with eta(1) (1855) -> eta eta '. Its mass and width are measured to be (1855 +/- 9(-1)(+6) MeV/c(2) and (188 +/- 18(-8)(+3) MeV, respectively, where the first uncertainties are statistical and the second are systematic, and its statistical significance is estimated to be larger than 19 sigma., For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.129.192002
- Published
- 2022
- Full Text
- View/download PDF
5. Observation of a State X(2600) in the pi(+) pi(-)eta' System in the Process J/psi -> gamma pi(+)pi(-)eta'
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Based on (10087 +/- 44) x 10(6) J/psi events collected with the BESIII detector, the process J/psi -> gamma pi(+)pi(-) eta'is studied using two largest decay channels of the eta' meson,eta' -> gamma pi(+)pi(-)and eta' -> eta pi(+)pi(-), eta ->gamma gamma.A new resonance, which we denote as the X(2600), is observed with a statistical significance larger than 20 sigma in the pi(|) pi(-) eta' invariant mass spectrum, and it has a connection to a structure around 1.5 GeV/c(2) in the pi(|) pi(-) invariant mass spectrum. A simultaneous fit on the pi(|) pi(-) eta' invariant mass spectra with the two eta' decay modes indicates that the mass and width of the X(2600) state are 2618.3 +/- 2.0(-1.4)+(16.3) MeV/c(2) and 195 +/- 5(-17)(+26) MeV, where the first uncertainties are statistical, and the second systematic., For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.129.042001
- Published
- 2022
- Full Text
- View/download PDF
6. Measurement of the e(+)e(-) -> Sigma(0)(Sigma)over-bar(0) cross sections at center-of-mass energies from 2.3864 to 3.0200 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J.H., Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J.H.
- Abstract
The Born cross sections of e(+)e(-) -> Sigma(0)(Sigma) over bar (0) are measured at center-of-mass energies from 2.3864 to 3.0200 GeV using data samples with an integrated luminosity of 328.5 pb(-1) collected with the BESIII detector operating at the BEPCII collider. The analysis makes use of a novel reconstruction method for energies near production threshold, while a single-tag method is employed at other center-of-mass energies. The measured cross sections are consistent with earlier results from BaBar, with a substantially improved precision. The cross-section lineshape can be well described by a perturbative QCD-driven energy function. In addition, the effective form factors of the Sigma(0) baryon are determined. The results provide precise experimental input for testing various theoretical predictions. (C) 2022 The Author(s). Published by Elsevier B.V., For complete list of authors see http://dx.doi.org/10.1016/j.physletb.2022.137187
- Published
- 2022
- Full Text
- View/download PDF
7. Measurement of e(+)e(-)-> K+K-pi(0) cross section and observation of a resonant structure
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Based on e(+)e(-) collision data collected by the BESIII detector at the BEPCII collider at center-of-mass energies from 2.000 to 3.080 GeV, a partial-wave analysis is performed for the process e(+)e(-)-> K+K-pi(0). The Born cross section of the process e(+)e(-)-> K+K-pi(0) and its subprocesses e(+)e(-)-> phi pi(0), K*+(892)K- and K2*+(1430)K- are measured. The results for e(+)e(-)-> K+K-pi(0) and phi pi(0) are consistent with the BaBar measurements and with improved precision. By analyzing the cross sections of the subprocesses e(+)e(-)-> K*+(892)K- and K2*+(1430)K-, a structure with mass M-R = (2190 +/- 19 +/- 37) MeV/c(2) and width Gamma(R) = (191 +/- 28 +/- 60) MeV is observed with a combined statistical significance of 7.1 sigma. The measured resonance parameters suggest it can be identified as the phi(2170), thus the results provide valuable input to understand the internal nature of this state., For complete list of authors see http://dx.doi.org/10.1007/JHEP07(2022)045
- Published
- 2022
- Full Text
- View/download PDF
8. Search for new hadronic decays of h(c) and observation of h(c) -> p(p)over-bar eta
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
A search for the hadronic decays of the h(c) meson to the final states p (p) over bar pi(+)pi(-)pi(0), p (p) over bar eta and p (p) over bar pi(0) via the process psi(3686) -> pi(0)(h)c is performed using (4.48 +/- 0.03) x 10(8) psi(3686) events collected with the BESIII detector. The decay channel h(c) -> p (p) over bar eta is observed for the first time with a significance greater than 5 sigma and a branching fraction of (6.41 +/- 1.74 +/- 0.53 +/- 1.00) x 10(-4), where the uncertainties are statistical, systematic, and that from the branching fraction of psi(3686) -> pi(0)(h)c. Strong evidence for the decay h(c) p (p) over bar pi(+)pi(-)pi(0) is found with a significance of 4.9 sigma and a branching fraction of (3.84 +/- 0.83 +/- 0.69 +/- 0.58) x 10(-3). The significances include systematic uncertainties. No clear signal of the decay h(c) -> p (p) over bar pi(0) is found, and an upper limit of 6.59 x 10(-4) on its branching fraction is set at the 90% confidence level., For complete list of authors see http://dx.doi.org/10.1007/JHEP05(2022)108Correction in: Journal of High Energy Physics volume 2023, Article number: 22 (2023)DOI: 10.1007/JHEP03(2023)022
- Published
- 2022
- Full Text
- View/download PDF
9. Probing CP symmetry and weak phases with entangled double-strange baryons
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Hansson, Joachim, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Hansson, Joachim, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Though immensely successful, the standard model of particle physics does not offer any explanation as to why our Universe contains so much more matter than antimatter. A key to a dynamically generated matter-antimatter asymmetry is the existence of processes that violate the combined charge conjugation and parity (CP) symmetry(1). As such, precision tests of CP symmetry may be used to search for physics beyond the standard model. However, hadrons decay through an interplay of strong and weak processes, quantified in terms of relative phases between the amplitudes. Although previous experiments constructed CP observables that depend on both strong and weak phases, we present an approach where sequential two-body decays of entangled multi-strange baryon-antibaryon pairs provide a separation between these phases. Our method, exploiting spin entanglement between the double-strange baryon and its antiparticle(2) (+), has enabled a direct determination of the weak-phase difference, (xi(P) - xi(S)) = (1.2 +/- 3.4 +/- 0.8) x 10(-2) rad. Furthermore, three independent CP observables can be constructed from our measured parameters. The precision in the estimated parameters for a given data sample size is several orders of magnitude greater than achieved with previous methods(3). Finally, we provide an independent measurement of the recently debated Lambda decay parameter alpha(Lambda) (refs. (4,5)). The Lambda(Lambda) over bar asymmetry is in agreement with and compatible in precision to the most precise previous measurement(4)., For complete list of authors see http://dx.doi.org/10.1038/s41586-022-04624-1
- Published
- 2022
- Full Text
- View/download PDF
10. Measurement of the Cross Section for e+e- -> Hadrons at Energies from 2.2324 to 3.6710 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Based on electron-positron collision data collected with the BESIII detector operating at the Beijing Electron-Positron Collider II storage rings, the value of R equivalent to sigma(e(+)e(-)-> hadrons)/sigma(e(+)e(-) -> mu(+)mu(-)) is measured at 14 center-of-mass energies from 2.2324 to 3.6710 GeV. The resulting uncertainties are less than 3.0% and are dominated by systematic uncertainties., For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.128.062004
- Published
- 2022
- Full Text
- View/download PDF
11. First Measurement of Polarizations in the Decay D-0 -> omega phi
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Using a data sample corresponding to an integrated luminosity of 2.93 fb(-1) collected at a center-of-mass energy root s = 3.773 GeV by the BESIII detector, the decay D-0 -> omega phi is observed for the first time. The branching fraction is measured to be (6.48 +/- 10.9 +/- 1 0.40) x 10(-4) with a significance of 6.3 sigma, where the first and second uncertainties are statistical and systematic, respectively. An angular analysis reveals that the phi and omega mesons from the D-0 -> omega phi decay are transversely polarized. The 95% confidence level upper limit on longitudinal polarization fraction is set to be less than 0.24, which is inconsistent with current theoretical expectations and challenges our understanding of the underlying dynamics in charm meson decays., For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.128.011803
- Published
- 2022
- Full Text
- View/download PDF
12. Observation of the electromagnetic Dalitz decay D*(0) -> D(0)e(+)e(-)
- Author
-
Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, and Wolke, Magnus
- Abstract
Based on 3.19 fb(-1) of e(+) e(-) collision data accumulated at the center-of-mass energy 4.178 GeV with the BESIII detector operating at the BEPCII collider, the electromagnetic Dalitz decay D*(0) -> D(0)e(+)e(-) is observed for the first time with a statistical significance of 13.2 sigma. The ratio of the branching fraction of D*(0) -> D(0)e(+)e(-) to that of D*(0) -> D-0 gamma is measured to be (11.08 +/- 0.76 +/- 0.49) x 10(-3). By using the world average value of the branching fraction of D*(0) -> D-0 gamma, the branching fraction of D*(0) -> D(0)e(+)e(-) is determined to be (3.91 +/- 0.27 +/- 0.17 +/- 0.10) x 10(-3), where the first uncertainty is statistical, the second is systematic and the third is from external input of the branching fraction for D*(0) -> D-0 gamma., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.112012
- Published
- 2022
- Full Text
- View/download PDF
13. Search for a CP-odd light Higgs boson in J/psi -> gamma A(0)
- Author
-
Adlarson, patad399, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Adlarson, patad399, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, and Wolke, Magnus
- Abstract
Using J/psi radiative decays from 9.0 billion J/psi events collected by the BESIII detector, we search for di-muon decays of a CP-odd light Higgs boson (A(0)), predicted by many new physics models beyond the Standard Model, including the next-to-minimal supersymmetric Standard Model. No evidence for the CP-odd light Higgs production is found, and we set 90% confidence level upper limits on the product branching fraction B(J/psi -> gamma A(0)) x B(A(0) -> mu(+)mu(-)) in the range of (1.2 - 778.0) x 10(-9) for 0.212 <= m(A0) <= 3.0 GeV/c(2). The new measurement is a 6-7 times improvement over our previous measurement, and is also slightly better than the BABAR measurement in the low-mass region for tan beta = 1., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.105.012008
- Published
- 2022
- Full Text
- View/download PDF
14. Measurement of Lambda baryon polarization in e(+) e(-) -> Lambda(Lambda)over-bar at root s=3.773 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Using a data sample of psi(3770) events collected with the BESIII detector at BEPCII corresponding to an integrated luminosity of 2.9 fb-1, we report a measurement of A spin polarization in e+ e- -> Lambda(Lambda) over bar at = root s = 3.773 GeV. The significance of polarization is found to be 2 sigma including the systematic uncertainty, which implies a zero phase between the transition amplitudes of the Lambda(Lambda) over bar helicity states. This phase can be interpreted in terms of psionic form factors, and is determined to be Delta Phi(Psi) = Phi(Psi)(E) - Phi(Psi)(M) = (71(-46)(+66) +/- 5)degrees. Similarly, the ratio between the form factors is found to be R-psi = vertical bar G(E)(Psi)/G(M)(Psi)vertical bar = 0.48(-0.35)(+0.21) +/- 0.03. The first uncertainties are statistical and the second systematic., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.105.L011101
- Published
- 2022
- Full Text
- View/download PDF
15. Partial wave analysis of J/psi -> gamma eta eta '
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
Based on a sample of (10.09 +/- 0.04 )x10(9) J /psi events collected with the BESIII detector operating at the BEPCII storage ring, a partial wave analysis of the decay J/psi -> gamma eta eta ' is performed. An isoscalar state with exotic quantum numbers J(P) (C)=1(-+), denoted as eta(1)(1855 ), has been observed for the first time with statistical significance larger than 19 sigma . Its mass and width are measured to be (1855 +/- 9(-1)(+6)) MeV /c(2) and (188 +/- 18(-8)(+3)) MeV , respectively. The first uncertainties are statistical and the second are systematic. The product branching fraction B (J /psi -> gamma eta(1)(1855 ))B (eta(1)(1855 )->eta eta ') is measured to be (2.70 +/- 0.41(-0.35)(+0.16))x10(-6) . In addition, an upper limit on the ratio of branching fractions B (f(0)(1710 )->eta eta ')/B (f(0)(1710 )->pi pi) is determined to be 1.61 x10(-3) at 90% confidence level, which lends support to the hypothesis that the f(0)(1710 ) has a large glueball component., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.106.072012
- Published
- 2022
- Full Text
- View/download PDF
16. Observation of D0(+) -> K-S(0)pi(0(+))omega and improved measurement of D-0 -> K- pi(+)omega
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Zou, J. H., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Abstract
By analyzing an e(+)e(-) annihilation data sample with an integrated luminosity of 2.93 fb(-1) taken at the center-of-mass energy of 3.773 GeV with the BESIII detector, we determine the absolute branching fractions of the hadronic decays D-0 -> K- pi(+)omega, D-0 -> K-S(0)pi(0)omega and D+ -> K-S(0)pi(+)omega to be (3.392 +/- 0.044(stat) +/- 0.085(syst))%, (0.848 +/- 0.046(stat) +/- 0.031(syst))%, and (0.707 +/- 0.041(stat) +/- 0.029(syst))%, respectively. The accuracy of the branching fraction measurement of the decay D-0 -> K- pi(+)omega is improved by a factor of seven compared to the world average value. The D-0 -> K-S(0)pi(0)omega and D+ -> K-S(0)pi(+)omega decays are observed for the first time., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.105.032009
- Published
- 2022
- Full Text
- View/download PDF
17. Measurement of integrated luminosities at BESIII for data samples at center-of-mass energies between 4.0 and 4.6 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, Liu, H. B., Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Liu, H. B.
- Abstract
The integrated luminosities of data samples collected in the BESIII experiment in 2016-2017 at center-of-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1% by analyzing large-angle Bhabha scattering events. The integrated luminosities of old datasets collected in 2010-2014 are updated by considering corrections related to detector performance, offsetting the effect of newly discovered readout errors in the electromagnetic calorimeter, which can haphazardly occur., For complete list of authors see http://dx.doi.org/10.1088/1674-1137/ac80b4
- Published
- 2022
- Full Text
- View/download PDF
18. Technical design report for the endcap disc DIRC
- Author
-
Davi, F., Calén, Hans, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Marciniewski, Pawel, Papenbrock, Michael, Pettersson, Joachim, Regina, Jenny, Schönning, Karin, Wolke, Magnus, Zmeskal, J., Davi, F., Calén, Hans, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Marciniewski, Pawel, Papenbrock, Michael, Pettersson, Joachim, Regina, Jenny, Schönning, Karin, Wolke, Magnus, and Zmeskal, J.
- Abstract
PANDA (anti-proton annihiliation at Darmstadt) is planned to be one of the four main experiments at the future international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. It is going to address fundamental questions of hadron physics and quantum chromodynamics using cooled antiproton beams with a high intensity and and momenta between 1.5 and 15 GeV/c. PANDA is designed to reach a maximum luminosity of 2 × 1032 cm−2 s. Most of the physics programs require an excellent particle identification (PID). The PID of hadronic states at the forward endcap of the target spectrometer will be done by a fast and compact Cherenkov detector that uses the detection of internally reflected Cherenkov light (DIRC) principle. It is designed to cover the polar angle range from 5° to 22° and to provide a separation power for the separation of charged pions and kaons up to 3 standard deviations (s.d.) for particle momenta up to 4 GeV/c in order to cover the important particle phase space. This document describes the technical design and the expected performance of the novel PANDA disc DIRC detector that has not been used in any other high energy physics experiment before. The performance has been studied with Monte-Carlo simulations and various beam tests at DESY and CERN. The final design meets all PANDA requirements and guarantees sufficient safety margins., For complete list of authors see http://dx.doi.org/10.1088/1361-6471/abb6c1
- Published
- 2022
- Full Text
- View/download PDF
19. Measurements of absolute branching fractions of D0→K0Lϕ, K0Lη, K0Lω, and K0Lη′
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
We report the first measurements of the absolute branching fractions of D0→K0Lϕ, D0→K0Lη, D0→K0Lω, and D0→K0Lη′, by analyzing 2.93 fb−1 of e+e− collision data taken at a center-of-mass energy of 3.773 GeV with the BESIII detector. Taking the world averages of the branching fractions of D0→K0Sϕ, D0→K0Sη, D0→K0Sω, and D0→K0Sη′, the K0S−K0L asymmetries R(D0,X) in these decay modes are obtained. The CP asymmetries in these decays are also determined. No significant CP violation is observed. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.105.092010Title in Web of Science: Measurements of absolute branching fractions of D-0 -> K-L(0)phi, K-L(0)eta, K-L(0)omega, and K-L(0)eta '
- Published
- 2022
20. Study of the decay D+s→K0SK0Sπ+ and observation of an isovector partner to f0(1710)
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using e(+)e(-) annihilation data corresponding to a total integrated luminosity of 6.32 fb(-1) collected at center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay D-s(+) -> (KSKS0)-K-0 pi(+) for the first time. An enhancement is observed in the K(S)(0)K(S)(0)( )mass spectrum near 1.7 GeV/c(2), which was not seen in D-s(+) -> K+K- pi(+) in an earlier work, implying the existence of an isospin one partner of the f(0)(1710). The branching fraction of the decay D-s(+) ->(KSKS0)-K-0 pi(+ )is determined to be B(D-s(+) -> (KSKS0)-K-0 pi(+)) = (0.68 +/- 0.04(stat) +/- 0.01(syst))%. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.105.L051103Title in WoS: Study of the decay D-s(+)-> (KSKS0)-K-0 pi(+) and observation of an isovector partner to f(0) (1710)
- Published
- 2022
21. Partial wave analysis of J/ψ → γη′η′
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using a sample of (10.09±0.04)×109 J/ψ events collected with the BESIII detector, a partial wave analysis of J/ψ→γη′η′ is performed. The masses and widths of the observed resonances and their branching fractions are reported. The main contribution is from J/ψ→γf0(2020) with f0(2020)→η′η′, which is found with a significance of greater than 25σ. The product branching fraction B(J/ψ→γf0(2020))⋅B(f0(2020)→η′η′) is measured to be (2.63±0.06(stat.)+0.31−0.46(syst.))×10−4. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.105.072002Title in Web of Science: Partial wave analysis of J/Psi -> gamma eta 'eta '
- Published
- 2022
22. Study of the processes χcJ → Ξ−Ξ¯¯¯¯ + and Ξ0 Ξ¯¯¯¯0
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,e(+)-e(-) Experiments ,Subatomic Physics ,Quarkonium ,Astronomy, Astrophysics and Cosmology ,Branching fraction ,QCD - Abstract
Using 448.1 x 10(6) psi(3686) decays collected with the BESIII detector at the BEPCII e(+)e(-) storage rings, the branching fractions and angular distributions of the decays chi(cJ) -> Xi(-)(Xi) over bar (+) and Xi(0)(Xi) over bar (0) ( J = 0, 1, 2) are measured based on a partial-reconstruction technique. The decays chi(c1) -> Xi(0)(Xi) over bar (0) and chi(c2) -> Xi(0)(Xi) over bar (0) are observed for the first time with statistical significances of 7 sigma and 15 sigma, respectively. The results of this analysis are in good agreement with previous measurements and have significantly improved precision. For complete and correct list of authors see http://dx.doi.org/10.1007/JHEP06(2022)074
- Published
- 2022
23. First Observation of the Direct Production of the χc1 in e+e− Annihilation
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Papenbrock, Michael, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Subatomic Physics - Abstract
We study the direct production of the JPC=1++ charmonium state χc1(1P) in electron-positron annihilation by carrying out an energy scan around the mass of the χc1(1P). The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process e+e−→χc1(1P)→γJ/ψ→γμ+μ− and the background processes e+e−→γISRJ/ψ→γISRμ+μ− and e+e−→γISRμ+μ− is observed by combining all the data samples. The χc1(1P) signal is observed with a significance of 5.1σ. This is the first observation of a C-even state directly produced in e+e− annihilation. The electronic width of the χc1(1P) resonance is determined to be Γee=(0.12+0.13−0.08) eV, which is of the same order of magnitude as theoretical calculations. For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.129.122001Title in Web of Science: First Observation of the Direct Production of the chi(c1) in e(+)e(-) Annihilation
- Published
- 2022
24. Study of the hc(11P1) meson via ψ(2S)→ π0hc decays at BESIII
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Papenbrock, Michael, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using 448 million ψ(2S) events, the spin-singlet P-wave charmonium state hc(11P1) is studied via the ψ(2S)→π0hc decay followed by the hc→γηc transition. The branching fractions are measured to be BInc(ψ(2S)→π0hc)×BTag(hc→γηc)=(4.22+0.27−0.26±0.19)×10−4, BInc(ψ(2S)→π0hc)=(7.32±0.34±0.41)×10−4, and BTag(hc→γηc)=(57.66+3.62−3.50±0.58)%, where the uncertainties are statistical and systematic, respectively. The hc(11P1) mass and width are determined to be M=(3525.32±0.06±0.15) MeV/c2 and Γ=(0.78+0.27−0.24±0.12) MeV. Using the center of gravity mass of the three χcJ(13PJ) mesons [M(c.o.g.)], the 1P hyperfine mass splitting is estimated to be Δhyp=M(hc)−M(c.o.g.)=(0.03±0.06±0.15) MeV/c2, which is consistent with the expectation that the 1P hyperfine splitting is zero at the lowest order. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.106.072007Title in Web of Science: Study of the h(c)(1(1)P(1)) meson via psi(2S) -> pi(0)h(c) decays at BESIII
- Published
- 2022
25. Observation of J/ψ Electromagnetic Dalitz Decays to X(1835), X(2120), and X(2370)
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using a sample of about 10(10) J/Psi events collected at a center-of-mass energy root s = 3.097 GeV with the BESIII detector, the electromagnetic Dalitz decays J/Psi -> e(+)e(-) pi(+)pi(-) eta', with eta' -> gamma pi(+)pi(-) and eta' -> pi(+)pi(-) eta, have been studied. The decay J/Psi -> e(+)e(-) X(1835) is observed with a significance of 15 sigma, and also an e(+)e(-) invariant-mass dependent transition form factor of J/Psi -> e(+)e(-) X(1835) is presented for the first time. The intermediate states X(2120) and X(2370) are also observed in the pi(+)pi(-) eta' invariant-mass spectrum with significances of 5.3 sigma and 7.3 sigma. The corresponding product branching fractions for J/Psi -> e(+)e(-) X, X -> pi(+) pi(-) eta' [X = X(1835), X(2120), and X(2370)] are reported. For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.129.022002Title in Web of Sience: Observation of J/Psi Electromagnetic Dalitz Decays to X(1835), X(2120), and X(2370)
- Published
- 2022
26. Search for a massless dark photon in Λ+c→pγ′ decay
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Papenbrock, Michael, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
A search for a massless dark photon gamma' is conducted using 4.5 fb(-1) of e(+)e(-) collision data collected at center-of-mass energies between 4.600 and 4.699 GeV with the BESIII detector at BEPCII. No significant signal is observed, and the upper limit on the branching fraction B(Lambda(+)(c) -> p gamma') is determined to be 8.0 x 10(-5) at 90% confidence level. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.106.072008Title in Web of Science: Search for a massless dark photon in Lambda(+)(c) -> p gamma' decay
- Published
- 2022
27. Measurement of the branching fraction of leptonic decay D-s(+) -> tau(+)nu(tau) via tau(+) -> pi(+)pi(0)(nu)over-bar tau( )
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,High Energy Physics::Phenomenology ,Subatomic Physics ,High Energy Physics::Experiment - Abstract
By analyzing 6.32 fb(-1) of e(+)e(-) annihilation data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we determine the branching fraction of the leptonic decay D-s(+) -> tau(+)nu(tau), with tau(+) -> pi(+)pi(0)(nu) over bar (tau), to be BDs+->nu tau = (5.29 +/- 0.25(stat) +/- 0.20(syst))%. We estimate the product of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cs vertical bar and the D-s(+) decay constant to be f(Ds+1) to be f(Ds+) vertical bar V-cs vertical bar = (244.8 +/- 5.8(stat) +/- 4.8(syst)) MeV, using the known values of the tau(+) and D-s(+) masses as well as the D-s(+) lifetime, together with our branching fraction measurement. Combining the value of vertical bar V-cs vertical bar obtained from a global fit in the standard model and fm from lattice quantum chromodynamics, we obtain f(Ds+) = (251.6 +/- 5.9(stat) +/- 4.9(syst)) MeV and vertical bar V-cs vertical bar = 0.980 +/- 0.023(stat) +/- 0.019(syst). Using the branching fraction of B-D(s+)->mu+nu mu = (5.35 +/- 0.21) x 10(-3), we obtain the ratio of the branching fractions BDs+->tau+nu tau/BDs+->mu+nu mu = 9.89 +/- 0.71, which is consistent with the standard model prediction of lepton flavor universality. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.032001
- Published
- 2021
28. Amplitude analysis and branching fraction measurement of D-s(+)-> K- K+ pi(+) pi(0)
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
The first amplitude analysis of the decay D-s(+)-> K- K+ pi(+) pi(0) is presented using the data samples, corresponding to an integrated luminosity of 6.32 fb(-1), collected with the BESIII detector at e(+)e(-) center-of-mass energies between 4.178 and 4.226 GeV. More than 3000 events selected with a purity of 97.5% are used to perform the amplitude analysis, and nine components are found necessary to describe the data. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.032011
- Published
- 2021
29. Observation of psi (3686) ->Xi (1530)(0) (Xi)over-bar (1530)(0) and Xi (1530)(0) (Xi)over-bar(0)
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using (448.1 +/- 2.9) x 10(6) psi (3686) events collected with the BESIII detector and a single-baryon tagging technique, we present the first observation of the decays psi(3686)-> Xi (1530)(0) (Xi) over bar (1530)(0) and Xi (1530)(0) (Xi) over bar (0). The branching fractions are measured to be B psi (3686)-> Xi (1530)(0) (Xi) over bar (1530)(0)) = (6.77 +/- 0.14 +/- 0.39 x 10(- 5) and B (psi(3686)-> Xi (1530)(0) (Xi) over bar (0) = (0.53 +/- 0.04 +/- 0.03) x 10(-5). Here, the first and second uncertainties are statistical and systematic, respectively. In addition, the parameter associated with the angular distribution for the decay psi (3686) ->Xi (1530)(0) (Xi) over bar (1530)(0) is determined to be alpha= 1/4 0.32 +/- 0.19 +/- 0.07, in agreement with theoretical predictions within one standard deviation. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.092012
- Published
- 2021
30. Cross section measurement of e(+)e(-) -> (KSKL0)-K-0 at root s=2.00-3.08 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
The cross sections of the process e(+)e(-) -> (KSKL0)-K-0 are measured at fifteen center-of-mass energies root s from 2.00 to 3.08 GeV with a total integrated luminosity of 582 pb(-1) and using the BESIII detector at the Beijing Electron Positron Collider. The results are found to be consistent with those obtained by BABAR. A resonant structure around 2.2 GeV is observed, with a mass and width of 2273.7 +/- 5.7 +/- 19.3 MeV/c(2) and 86 +/- 44 +/- 51 MeV, respectively, where the first uncertainties are statistical and the second ones are systematic. The product of its radiative width (Gamma(e+e-)) with its branching fraction to (KSKL0)-K-0 (Br-KS0KL0) is 0.9 +/- 0.6 +/- 0.7 eV. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.092014
- Published
- 2021
31. Study of the decay D+s→π+π+π−η and observation of the W-annihilation decay D+s→a0(980)+ρ0
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Subatomic Physics - Abstract
The decay D-s(+) -> pi(+) pi(+) pi(-)eta is observed for the first time, using e(+)e(-) collision data corresponding to an integrated luminosity of 6.32 fb(-1), collected by the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV. The absolute branching fraction for this decay is measured to be B(D-s(+) -> pi(+) pi(+) pi(-)eta) = (3.12 +/- 0.13(stat) +/- 0.09(syst))% The first amplitude analysis of this decay reveals the substructures in D-s(+) -> pi(+) pi(+) pi(-)eta and determines the relative fractions and the phases among these substructures. The dominant intermediate process is D-s(+) -> a(1)(1260)(+)eta, a(1)(1260)(+) -> rho(770)(0)pi(+) with a branching fraction of (1.73 +/- 0.14(stat) +/- 0.08(syst))%. We also observe the W-annihilation process D-s(+) -> a(0)(980)(+) rho(770)(0), a(0)(980)(+) -> pi(+)eta. with a branching fraction of (0.21 +/- 0.08(stat) +/- 0.05(syst))%, which is larger than the branching fractions of other measured pure W-annihilation decays by 1 order of magnitude. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.L071101
- Published
- 2021
32. Measurements of Born cross sections of e(+)e(-) -> D-s* + D-sJ(-) + c.c
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
The Born cross sections are measured for the first time for the processes e(+)e(-) -> D-s* + D-sJ(-) + c.c. and e(+)e(-) -> D-s* + D-s1(2460)(-) + c:c: at the center-of-mass energy root p = 4.600 GeV, 4.612 GeV, 4.626 GeV, 4.640 GeV, 4.660 GeV, 4.68 GeV, and 4.700 GeV, and for e(+)e(-) -> D-s* + D(s1()2536)(-) +c.c. at root s = 4.660 GeV, 4.680 GeV, and 4.700 GeV, using data samples collected with the BESIII detector at the BEPCII collider. No structures are observed in cross-section distributions for any of the processes. For complete list of authors see http://dx.doi.org/None
- Published
- 2021
33. Search for the lepton number violating decay Sigma(-) -> pe(-) e(-) and the rare inclusive decay Sigma(-) -> Sigma(+) X
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using a data sample of (1310.6 +/- 7.0) x 10(6) J/psi events taken with the BESIII detector at the center-of-mass energy of 3.097 GeV, we search for the first time for the lepton number violating decay Sigma(-) -> pe(-) e(-) and the rare inclusive decay Sigma(-) -> Sigma(+) X, where X denotes any possible particle combination. The Sigma(-) candidates are tagged in J/psi -> (Sigma) over bar (1385)(+)Sigma(-) decays. No signal candidates are found, and the upper limits on the branching fractions at the 90% confidence level are determined to be B(Sigma(-) -> pe(-) e(-)) < 6.7 x 10(-5) and B(Sigma(-) -> Sigma(+) X) < 1.2 x 10(-4). For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.103.052011
- Published
- 2021
34. Study of e(+)e(-) -> 2(p(p)over-bar) at center-of-mass energies between 4.0 and 4.6 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using data taken at 23 center-of-mass energies between 4.0 and 4.6 GeV with the BESIII detector at the Beijing Electron Positron Collider and with a total integrated luminosity of approximately 15 fb(-1), the process e(+)e(-) -> 2(p (p) over bar) is studied for the first time. The Born cross sections for e(+)e(-) -> 2(p (p) over bar) are measured, and no significant structure is observed in the lineshape. The baryon pair (pp and (p) over bar(p) over bar) invariant mass spectra are consistent with phase space, therefore no hexaquark or di-baryon state is found. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.103.052003
- Published
- 2021
35. Search for the rare semi-leptonic decay J/psi -> D(-)e(+)nu(e) + c.c
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,e(+)-e(-) Experiments ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using 10.1 x 10(9)J/ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy s = 3.097 GeV and collected with the BESIII detector, we present a search for the rare semi-leptonic decay J/psi -> D(-)e(+)nu (e) + c.c. No excess of signal above background is observed, and an upper limit on the branching fraction B(J/psi -> D(-)e(+)nu (e)+c. c.)For complete list of authors see http://dx.doi.org/10.1007/JHEP06(2021)157
- Published
- 2021
36. Measurement of the Absolute Branching Fraction of D+s→τ+ντ via τ+ → e+νe¯ντ
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Subatomic Physics - Abstract
Using a dataset of 6.32 fb−1 of e+e− annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D+s→τ+ντ via τ+→e+νe¯ντ, and find BD+s→τ+ντ = (5.27±0.10±0.12)×10−2, where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with fD+s from lattice quantum chromodynamics calculations or the |Vcs| from the CKMfitter group, we extract |Vcs|=0.978±0.009±0.012 and fD+s = (251.1±2.4±3.0) MeV, respectively. Combining our result with the world averages of BD+s→τ+ντ and BD+s→μ+νμ, we obtain the ratio of the branching fractions BD+s→τ+ντ/BD+s→μ+νμ = 9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality. For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.127.171801
- Published
- 2021
37. Observation of η′→π+π−μ+μ−
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Using (1310.6 +/- 7.0) x 10(6) J/psi events acquired with the BESIII detector at the BEPCII storage rings, the decay eta' -> pi(+)pi(-)mu(+)mu(-) is observed for the first time with a significance of 8 sigma via the process J/psi -> gamma eta'. We measure the branching fraction of eta' -> pi(+)pi(-)mu(+)mu(-) to be B(eta' -> pi(+)pi(-)mu(+)mu(-)) = (1.97 +/- 0.33(stat) +/- 0.19(syst)) x 10(-5), where the first and second uncertainties are statistical and systematic, respectively. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.103.072006Title in WoS: Observation of eta ' -> pi(+)pi(-)mu(+)mu(-)
- Published
- 2021
38. Measurement of branching fractions of J/psi and psi(3686) decays to Sigma(+) and (Sigma)over-bar(-)
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,e(+)-e(-) Experiments ,Subatomic Physics ,Branching fraction ,QCD - Abstract
Using 1310.6 x 10(6) J/psi and 448.1 x 10(6) psi(3686) events collected with the BESIII detector, the branching fractions of J/psi decays to Sigma(+)(Sigma) over bar (-) is measured to be (10.61 +/- 0.04 +/- 0.36) x 10(-4), which is significantly more precise than the current world average. The branching fractions of psi(3686) decays to Sigma(+)(Sigma) over bar (-) is measured to be (2.52 +/- 0.04 +/- 0.09) x 10(-4), which is consistent with the previous measurements. In addition, the ratio of beta(psi(3686) -> Sigma(+)(Sigma) over bar (-)) / beta(J/psi -> Sigma(+)(Sigma) over bar (-)) is determined to be (23.8 +/- 1.1)% which violates the "12% rule". For complete list of authors see http://dx.doi.org/10.1007/JHEP11(2021)226
- Published
- 2021
39. Search for the X (2370) and observation of eta(c) -> eta eta eta ' in J/psi -> gamma eta eta eta '
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, J., Ikegami Andersson, Walter, Johansson, T., Kupsc, Andrzej, Pettersson, J., Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology ,High Energy Physics::Experiment ,Nuclear Experiment - Abstract
Using a sample of 1.31 x 10(9) J/psi events collected with the BESIII detector, we perform a study of J/psi -> gamma eta eta eta' to search for the X(2370) and eta(c) in the eta eta eta' invariant mass distribution. No significant signal for the X(2370) is observed, and we set an upper limit for the product branching fraction of B(J/psi -> gamma X(2370) . B(X(2370) -> eta eta eta') < 9.2 x 10(-6) at the 90% confidence level. A clear eta(c) signal is observed for the first time, yielding a product branching fraction of B(J/psi -> gamma eta(c)).B(eta c -> eta eta eta') = (4.86 +/- 0.62(stat) +/- 0.45(sys)) x 10(-5). For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.103.012009
- Published
- 2021
40. Observation of a near-threshold enhancement in the Λλ mass spectrum from e+e- → Φ Λλ at √s is from 3.51 to 4.60 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology ,High Energy Physics::Experiment - Abstract
The process e(+)e(-) -> phi Lambda(Lambda) over bar is studied using data samples collected with the BESIII detector at the BEPCII Collider at center of mass energies root S ranging from 3.51 GeV to 4.60 GeV. An enhancement is observed near the threshold of Lambda(Lambda) over bar. The lineshape of this enhancement is studied in different approaches, including fit with a Breit-Wiper function or a reversed exponential function. The Breit-Wigner function has a mass of (2262 +/- 4 +/- 28) McV/c(2) and a width of (72 +/- 5 +/- 43) MeV, where the quoted uncertainties are statistical and systematic, respectively. The rising rate of the reversed exponential function is measured as 33 +/- 11 +/- 6 MeV/c(2). For the Lambda(Lambda) over bar system, the J(PC) quantum numbers of 0(-+) and 0(+)(+) are rejected, while other J(PC) hypotheses are possible, according to the helicity-angle study. The energy-dependent cross section of the e(+)e(-) -> phi Lambda(Lambda) over bar process is measured for the first time in this energy region, and contributions from excited psi states and vector charmoniumlike Y-states are investigated. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.052006Title in Web of Science: Observation of a near-threshold enhancement in the Lambda(Lambda)over-bar mass spectrum from e(+)e(-) -> phi Lambda(Lambda)over-bar at root S is from 3.51 to 4.60 GeV
- Published
- 2021
41. Observation of D0→K1(1270)−e+νe
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Subatomic Physics - Abstract
Using 2.93 fb(-1) of e(+)e(-) collision data taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, the observation of the D-0 -> K-1 (1270)(-)e(+)nu(e) semileptonic decay is presented. The statistical significance of the decay D-0 -> K-1 (1270)e(+)nu(e) is greater than 10 sigma. The branching fraction of D-0 -> K-1 (1270)(-)e(+)nu(e) is measured to be (1.09 +/- 0.13(-0.16)(+0.09) +/- 0.12) x 10(-3). Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of K-1 (1270)(-) -> K-pi(+)pi(-). The fraction of longitudinal polarization in D-0 -> K-1 (1270)(-)e(+)nu(e) is determined for the first time to be 0.50 +/- 0.19(stat )+/- 0.08(syst). For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.127.131801Title in WoS: Observation of D-0 -> K-1 (1270) (-)e(+)nu(e)
- Published
- 2021
42. Measurement of the Born cross sections for e+e- → η'π+ π- at center-of-mass energies between 2.00 and 3.08 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
The Born cross sections for the process e+e−→η′π+π− at different center-of-mass energies between 2.00 and 3.08 GeV are reported with improved precision from an analysis of data samples collected with the BESIII detector operating at the BEPCII storage ring. An obvious structure is observed in the Born cross section line shape. Fit as a Breit-Wigner resonance, it has a statistical significance of 6.3σ and a mass and width of M=(2111±43±25) MeV/c2 and Γ=(135±34±30) MeV, where the uncertainties are statistical and systematic, respectively. These measured resonance parameters agree with the measurements of BABAR in e+e−→η′π+π− and BESIII in e+e−→ωπ0 within two standard deviations. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.103.072007Title in Web of Science: Measurement of the Born cross sections for e(+)e(-) -> eta'pi(+) pi(-) a t center-of-mass energies between 2.00 and 3.08 GeV
- Published
- 2021
43. Measurements of the branching fractions of psi(3686) -> (Sigma)over-bar(0)Lambda + c.c. and chi cJ(J=0,1,2) -> Lambda(Lambda)over-bar
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Subatomic Physics - Abstract
Based on 4.481 x 10(8) psi(3686) events collected with the BESIII detector at BEPCII, the branching fraction of the isospin violating decay psi(3686)-> (Sigma) over bar0 Lambda+c.c: is measured to be (1.60 +/- 0.31 +/- 0.13 +/- 0.58) x 10(-6), where the first uncertainty is statistical, the second is systematic, and the third is the uncertainty arising from interference with the continuum. This result is significantly smaller than the measurement based on CLEO-c data sets. The decays chi cJ ->Lambda(Lambda) over bar are measured via psi(3686)->gamma gamma(cJ), and the branching fractions are determined to be B(chi(c0) -> Lambda(Lambda) over bar) = (3.64 +/- 0.10 +/- 0.10 +/- 0.07) x 10(-4), B(chi(c1) -> Lambda(Lambda) over bar) = (1.31 +/- 0.06 +/- 0.06 +/- 0.03) x 10(-4), B(chi(c2) -> Lambda(Lambda) over bar) = (1.91 +/- 0.08 +/- 0.17 +/- 0.04) x 10(-4), where the third uncertainties are systematic due to the psi(3686) -> gamma chi(cJ) branching fractions. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.103.112004
- Published
- 2021
44. Study of the process e(+)e(-) -> phi eta at center-of-mass energies between 2.00 and 3.08 GeV
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
The process e(+)e(-) -> phi eta is studied at 22 center-of-mass energy points (root s) between 2.00 and 3.08 GeV using 715 pb(-1) of data collected with the BESIII detector. The measured Born cross section of e(+)e(-) -> phi eta is found to be consistent with BABAR measurements, but with improved precision. A resonant structure around 2.175 GeV is observed with a significance of 6.9 sigma with mass (21635 +/- 6.2 +/- 3.0) MeV/c(2) and width (31.1(-11.6)(+21.1) +/- 1.1) MeV, where the first uncertainties are statistical and the second are systematic. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.032007
- Published
- 2021
45. Measurement of the inclusive branching fraction for ψ(3686) →K0S+anything
- Author
-
Ablikim, M., Adlarson, Patrik, Biernat, Jacek, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Inclusive branching fraction ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,BESIII ,Astronomy, Astrophysics and Cosmology ,K-S(0) ,psi(3686) - Abstract
Using 5.9 pb(-1) of e(+)e(-) annihilation data collected at center-of-mass energies from 3.640 to 3.701 GeV with the BESIII detector at the BEPCII Collider, we measure the observed cross sections of e(+)e(-) -> (KSX)-X-0 (where X = anything). From a fit to these observed cross sections with the sum of continuum and psi(3686) and J/psi Breit-Wigner functions and considering initial state radiation and the BEPCII beam energy spread, we obtain for the first time the product of psi(3686) leptonic width and inclusive decay Physics Letters 820 (2021) 136576 branching fraction Gamma B-ee(psi)(3686)(psi(3686) -> (KSX)-X-0) = (373.8 +/- 6.7 +/- 20.0) eV, and assuming Gamma(ee)(psi)((3686)) is (2.33 +/- 0.04) keV from PDG value, we measure B(psi(3686) ->(KSX)-X-0) = (16.04 +/- 0.29 +/- 0.90)%, where the first uncertainty is statistical and the second is systematic. Title in WoS: Measurement of the inclusive branching fraction for psi (3686) -> K-S(0) + anythingFor complete list of authors see http://dx.doi.org/10.1016/j.physletb.2021.136576
- Published
- 2021
46. Measurement of the cross section for e(+)e(-) -> Lambda(Lambda)over-bar and evidence of the decay psi(3770) -> Lambda(Lambda)over-bar
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology ,High Energy Physics::Experiment - Abstract
The Born cross section of the process e(+)e(-) ->Lambda(Lambda) over bar over line is measured at 33 center-of-mass energies between 3.51 and 4.60 GeV using data corresponding to the total integrated luminosity of 20.0 fb(-1) collected with the BESIII detector at the BEPCII collider. Describing the energy dependence of the cross section requires a contribution from the psi(3770) -> Lambda(Lambda) over bar decay, which is fitted with a significance of 4.6 - 4.9 sigma including the systematic uncertainty. The lower bound on its branching fraction is 2.4 x 10(-6) at the 90% confidence level (C.L.), at least an order of magnitude larger than expected from predictions using a scaling based on observed electronic widths. This result indicates the importance of effects from vector charmonium(like) states when interpreting data in terms of e.g., electromagnetic structure observables. The data do not allow for definite conclusions on the interplay with other vector charmonium(like) states, and we set 90% C.L. upper limits for the products of their electronic widths and the branching fractions. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.L091104
- Published
- 2021
47. Measurement of the doubly Cabibbo-suppressed decay D+→K+π+π−π0 with semileptonic tags
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Subatomic Physics - Abstract
We propose a new semileptonic tag method to study the doubly Cabibbo-suppressed D decay in psi(3770) -> D (D) over bar reaction. Utilizing the dataset corresponding to an integrated luminosity of 2.93 fb(-1) at a center-of-mass energy of 3.773 GeV collected by the BESIII detector, we determine the branching fraction for D+ -> K+pi(+)pi(-)pi(0) to be (1.03 +/- 0.12(stat) +/- 0.06(syst)) x 10(-3), in which the contributions from narrow intermediate resonances, D+ -> K+eta, D+ -> K+omega, and D+ -> K+phi have been excluded. Combining the world average of the branching fraction of D+ -> K+pi(+)pi(-)pi(0), we determine B(D+ -> K+pi(+)pi(-)pi(0))/B(D+ -> K+pi(+)pi(-)pi(0)) = (1.65 +/- 0.21)%, corresponding to (5.73 +/- 0.73) tan(4)theta(c), where theta(c) is the Cabibbo mixing angle. These results are consistent with our previous measurement with hadronic tags but are significantly larger than other doubly Cabibbo-suppressed decays in the charm sector. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.072005Title in WoS: Measurement of the doubly Cabibbo-suppressed decay D+ -> K+pi(+)pi(-)pi(0) with semileptonic tags
- Published
- 2021
48. Observation of the decays chi(cJ) -> nK(S)(0) (Lambda)over-bar + c.c
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,e(+)-e(-) Experiments ,Subatomic Physics - Abstract
By analyzing 4.48 x 10(8) psi(3686) events collected with the BESIII detector, we observe the decays chi(cJ) -> nK(S)(0) (Lambda) over bar + c.c. (J = 0, 1, 2) for the first time, via the radiative transition psi(3686) -> gamma chi(cJ). The branching fractions are determined to be (6.65 +/- 0.26(stat)+/- 0.41(syst)) x 10(-4), (1.66 +/- 0.12(stat) +/- 0.12(syst)) x 10(-4), and (3.58 +/- 0.16(stat) +/- 0.23(syst)) x 10(-4) for J = 0, 1, and 2, respectively. For complete list of authors see http://dx.doi.org/10.1007/JHEP11(2021)217
- Published
- 2021
49. Measurement of the branching fraction for ψ(3686)→ωK0SK0S
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Astronomi, astrofysik och kosmologi ,Subatomic Physics ,Astronomy, Astrophysics and Cosmology - Abstract
Analyzing (448.1 +/- 2.9) x 10(6) psi (3686) events collected with the BESIII detector at the BEPCII collider, the psi(3686) -> omega(KSKS0)-K-0 decay is observed for the first time. The branching fraction for this decay is determined to be B-psi(3686)->omega KS0KS0 = (7.04 +/- 0.39 +/- 0.36) x 10(-5), where the first uncertainty is statistical and the second is systematic. Title in WoS: Measurement of the branching fraction for psi (3686) ->omega(KSKS0Y)-K-0For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.092003
- Published
- 2021
50. Determination of the absolute branching fractions of D0 → K-e+νe and D+ → K0e+νe
- Author
-
Ablikim, M., Adlarson, Patrik, Ikegami Andersson, Walter, Johansson, Tord, Kupsc, Andrzej, Pettersson, Joachim, Schönning, Karin, Thorén, Viktor, Wolke, Magnus, and Zou, J. H.
- Subjects
Subatomär fysik ,Subatomic Physics - Abstract
Using 2.93 fb(-1) of e(+)e(-) collision data collected with the BESIII detector at a center-of-mass energy of 3.773 GeV, we measure the absolute branching fractions of the decays D-0 -> K(-)e(+)nu(e) and D+ -> (K) over bar (0)e(+)nu(e) to be (3.567 +/- 0.031(stat) +/- 0.025(syst))% and (8.68 +/- 0.14(stat) +/- 0.16(syst))%, respectively. Starting with the process e(+)e(- ) -> D (D) over bar, a new reconstruction method is employed to select events that contain candidates for both D -> (K) over bare(+)nu(e) and (D) over bar -> Ke(-)(nu) over bar (e) decays. The branching fractions reported in this work are consistent within uncertainties with previous BESIII measurements that selected events containing D -> (K) over bare(+)nu(e) and hadronic (D) over bar decays. Combining our results with the lifetimes of the D degrees and D+ mesons and the previous BESIII measurements leads to a ratio of the two decay partial widths of (Gamma) over bar (D0 -> K-e+)(nu e)/(Gamma) over bar (D+ -> (K) over bar 0e+)(nu e) = 1.039 +/- 0.021. This ratio supports isospin symmetry in the D-0 -> K(-)e(+)nu(e) and D+ -> (K) over bar (0)e(+)nu(e) decays within 1.9 sigma. For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.104.052008Title in Web of Science: Determination of the absolute branching fractions of D-0 -> K(-)e(+)nu(e) and D+ -> (K)over-bar(0)e(+)nu(e)
- Published
- 2021
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.